Literary usage of Gestation period

Below you will find example usage of this term as found in modern and/or classical literature:

1.Proceedings of the Cambridge Philosophical Society by Cambridge Philosophical Society (1908)"(1) a short gestation period, from 53 to 61 days; in which there are 69 litters
recorded with an average of 117-82 dogs; I have divided the period of ..."

2.Pork-production by William Wesley Smith, Robert Alexander Craig (1920)"Length of gestation period. The time elapsing between breeding and farrowing is
known as the gestation period. During this time each of the fertilized eggs ..."

3.The Rat: Reference Tables and Data for the Albino Rat (Mus Norvegicus by Henry Herbert Donaldson (1915)"The gestation period in lactating albino rats is of normal length if the female
... The gestation period may be prolonged from one to six days if an albino ..."

4.Successful Farming; a Ready Reference on All Phases of Agriculture for by Frank Duane Gardner (1916)"gestation period.—The farmer or livestock breeder must keep a record of the breeding
... The gestation period varies with the various classes of animals. ..."